Ground maintenance vehicles adapted to support and operate any one of a number of ground-engaging implements are known. For instance, tractors may support such implements as cutting decks, snow throwers, sweepers, etc. While some of these implements may be self-powered (e.g., tow-behind cutting decks having on-board engines), most implements typically receive take-off power from a driveshaft of the vehicle's engine. While the present invention is applicable to drive systems for use with most any type of power equipment and implement combination, it will, for the sake of brevity, be described with respect to a commercial riding mower having a belly-mounted or front-mounted cutting deck.
For mowers having large engines, e.g., 20 horsepower or more, the engine may be mounted such that the engine output shaft (driveshaft) protrudes horizontally from a rear side of the engine. Similarly, a jackshaft, which receives power from the driveshaft, may be coupled to the cutting deck. In many configurations, power is provided from the drive shaft to the jackshaft via a belt drive system.
Belt drive systems found on riding lawn mowers typically include an endless belt extending between a pulley attached to the driveshaft, and a pulley attached to the jackshaft. An idler pulley may be used to selectively tension the belt and deliver power from the driveshaft to the jackshaft of the cutting deck. To disengage power to the cutting deck, the idler pulley may be moved away from the belt until belt tension is sufficiently relaxed.
While effective at terminating delivery of power to the cutting deck, system inertia may result in rotation of the cutting blades even after power delivery is stopped. As a result, it is sometimes desirable to brake the drive system so that the cutting blades are stopped more quickly. This is typically accomplished by a separate brake element that may be selectively positioned in contact with a moving component of the cutting deck system. For example, some mowers utilize an independently actuatable band brake that can be applied to a spindle or pulley mounted to (or otherwise associated with) the cutting deck.
While such brake systems are able to stop the cutting blades quickly, problems remain. For example, the movement of both the idler pulley and the brake element generally requires a sophisticated mechanism (or two separate mechanisms). As a result, these brake systems may increase complexity (and ultimately, cost) of the drive system and, consequently, the mower.